Why does Yu-Fang's father arrange for her to be seen by General Xue as noted in the nonfiction book, Wild Swans: Three Daughters of China?

Yu-Fang's father arranges for Yu-Fang to be seen by the General, hoping he'll be taken by her beauty. He is and he soon offers to take her as a concubine, paying Yu-Fang handsomely for her.